Importance: There has been only one human study on the modification of gut flora as a therapeutic tool for improvement of MHE in cirrhosis, however that study included alcoholic liver disease and comprised of Chinese patients, therefore etiologies of liver diseases studied were different from those predominant in the United States. Since MHE can adversely affect quality of life and overall prognosis, simple, targeted therapies are needed to treat it. We believe that our pilot study will help delineate human gut flora as a definite target for therapy of cirrhosis and MHE and pave the way for future large-scale studies on this subject.